Originally Posted by 98hotrodfatboy

If you didn't know that it had a tuner when you purchased the bike how do you know what tune to put into it?? Do you even know if any other work was done on the bike.. At this point it's a crap shoot, somebody should be able to get the original tune that was in there and reload it..
Which is what I would do...

Originally Posted by limacharlie

I’m at the end of my rope on this one.

I bought this 2012 Dyna Super Glide Custom in August. Love it. She rips. In November, I feel like I won the lottery when I realized there was a V&H FP4 tucked under the seat. I don’t know what was flashed to the ECU when I bought the bike, but as soon as I flashed a map with the FP4 I started getting diagnostic codes for the TPS (P0122 and P0123 high/low open). Weird coincidence, I have no idea.

Screw it, threw $50 at Dennis Kirk and bought a new TPS. But… codes won’t clear and the issue is still there. I don’t think it has had an impact on performance so I just dealt with looking at the check engine light all winter.

Today I finally got around to diagnosing what the hell is going on. Bought an OEM TPS from the local Harley joint and ran into the same issue. But I at least was able to start seeing an issue. When the TPS is plugged in but not hooked up to the throttle body I get no TPS codes. But when I put the TPS on loosely without screwing it in, it’s not aligned with the bolts (rotated further than the bolt pattern expects). This means that when it’s not hooked up, TPS shows 0% throttle position and when it’s hooked up it shows 7% throttle position. So… it’s not a TPS issue, it’s an issue with the throttle getting stuck open a little.

The throttle cables aren’t holding it open. The throttle stop screw on the throttle body isn’t keeping it from closing. I sprayed it real good with throttle body cleaner. Nothing helps.

What would keep the throttle from closing to the 0% point on the TPS? I genuinely don’t know what else to check and I’m so f***ing frustrated. Or… am I missing something to reset the zero point of the TPS???

Sorry for ramblings and typos. If something doesn’t make sense, please ask. Today’s post is sponsored by Daydrinking with Miller Lite.

I really really appreciate some guidance from the community on this one before I take it to a mechanic.

Originally Posted by limacharlie

It had the Vance & Hines FP4 tuner installer when I bought it. Assumed it was flashed to stock or had a tune from the FP4 already. The FP4 doesn’t have a ton of parameters… pick your bike, pike your exhaust, pick your baffles…. Boom, then run autotune to fine tune it. Pretty easy.

Already flashed it back to stock, then worked with V&H to use that as the new “stock map” on the FP4, then flashed the new map. Good to go. No codes. This bike rips now.